Evaluation of sedation for standing clinical procedures in horses using detomidine combined with buprenorphine.

Objectives: To examine the effect of including buprenorphine with detomidine for sedation of horses undergoing clinical procedures.

Study Design: Partially blinded, randomised, prospective clinical field trial.

Animals: Eighty four client-owned horses scheduled for minor surgery or diagnostic investigation under standing sedation.

Methods: The effects of buprenorphine (5 μg kg(-1) ) (Group B, n = 46) or placebo (5% glucose solution) (Group C, n = 38) in combination with detomidine (10 μg kg(-1) ) were compared in standing horses undergoing minor clinical procedures. The primary outcome measure was successful completion of the procedure. The degree of sedation and ataxia were scored using simple descriptive scales. Heart and respiratory rates were recorded at 15-30 minute intervals. Parametric data from each group were compared using anova or t-test and non parametric data using the Mann-Whitney U test.

Results: The procedure was carried out successfully in 91% of Group B and 63% of Group C (p < 0.01). Repeat dosing was required in 24% of Group B and 32% of Group C (p < 0.05). Sedation was more profound and lasted longer (60 versus 45 minutes) in Group B (p < 0.01). Ataxia occurred after detomidine, increased after buprenorphine but not glucose administration, was more profound in group B and lasted longer (60 versus 30 minutes) p < 0.001). Heart and respiratory rates remained within normal limits in both groups and there were no serious adverse events.

Conclusions And Clinical Relevance: Buprenorphine 5 and 10 μg kg(-1) enhanced the sedation produced by detomidine 10 and 20 μg kg(-1) with minor side effects similar to other alpha2 agonist/opioid combinations. Detomidine-buprenorphine sedation is suitable for standing procedures in horses.